xref: /freebsd/lib/libmemstat/memstat_malloc.c (revision 345628080df9217ac3a2c45b779d482b54b26383)
1 /*-
2  * Copyright (c) 2005 Robert N. M. Watson
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <sys/param.h>
30 #include <sys/malloc.h>
31 #include <sys/sysctl.h>
32 
33 #include <err.h>
34 #include <errno.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 
39 #include "memstat.h"
40 #include "memstat_internal.h"
41 
42 /*
43  * Extract malloc(9) statistics from the running kernel, and store all memory
44  * type information in the passed list.  For each type, check the list for an
45  * existing entry with the right name/allocator -- if present, update that
46  * entry.  Otherwise, add a new entry.  On error, the entire list will be
47  * cleared, as entries will be in an inconsistent state.
48  *
49  * To reduce the level of work for a list that starts empty, we keep around a
50  * hint as to whether it was empty when we began, so we can avoid searching
51  * the list for entries to update.  Updates are O(n^2) due to searching for
52  * each entry before adding it.
53  */
54 int
55 memstat_sysctl_malloc(struct memory_type_list *list, int flags)
56 {
57 	struct malloc_type_stream_header *mtshp;
58 	struct malloc_type_header *mthp;
59 	struct malloc_type_stats *mtsp;
60 	struct memory_type *mtp;
61 	int count, hint_dontsearch, i, j, maxcpus;
62 	char *buffer, *p;
63 	size_t size;
64 
65 	hint_dontsearch = LIST_EMPTY(&list->mtl_list);
66 
67 	/*
68 	 * Query the number of CPUs, number of malloc types so that we can
69 	 * guess an initial buffer size.  We loop until we succeed or really
70 	 * fail.  Note that the value of maxcpus we query using sysctl is not
71 	 * the version we use when processing the real data -- that is read
72 	 * from the header.
73 	 */
74 retry:
75 	size = sizeof(maxcpus);
76 	if (sysctlbyname("kern.smp.maxcpus", &maxcpus, &size, NULL, 0) < 0) {
77 		if (errno == EACCES || errno == EPERM)
78 			list->mtl_error = MEMSTAT_ERROR_PERMISSION;
79 		else
80 			list->mtl_error = MEMSTAT_ERROR_DATAERROR;
81 		return (-1);
82 	}
83 	if (size != sizeof(maxcpus)) {
84 		list->mtl_error = MEMSTAT_ERROR_DATAERROR;
85 		return (-1);
86 	}
87 
88 	if (maxcpus > MEMSTAT_MAXCPU) {
89 		list->mtl_error = MEMSTAT_ERROR_TOOMANYCPUS;
90 		return (-1);
91 	}
92 
93 	size = sizeof(count);
94 	if (sysctlbyname("kern.malloc_count", &count, &size, NULL, 0) < 0) {
95 		if (errno == EACCES || errno == EPERM)
96 			list->mtl_error = MEMSTAT_ERROR_PERMISSION;
97 		else
98 			list->mtl_error = MEMSTAT_ERROR_VERSION;
99 		return (-1);
100 	}
101 	if (size != sizeof(count)) {
102 		list->mtl_error = MEMSTAT_ERROR_DATAERROR;
103 		return (-1);
104 	}
105 
106 	size = sizeof(*mthp) + count * (sizeof(*mthp) + sizeof(*mtsp) *
107 	    maxcpus);
108 
109 	buffer = malloc(size);
110 	if (buffer == NULL) {
111 		list->mtl_error = MEMSTAT_ERROR_NOMEMORY;
112 		return (-1);
113 	}
114 
115 	if (sysctlbyname("kern.malloc_stats", buffer, &size, NULL, 0) < 0) {
116 		/*
117 		 * XXXRW: ENOMEM is an ambiguous return, we should bound the
118 		 * number of loops, perhaps.
119 		 */
120 		if (errno == ENOMEM) {
121 			free(buffer);
122 			goto retry;
123 		}
124 		if (errno == EACCES || errno == EPERM)
125 			list->mtl_error = MEMSTAT_ERROR_PERMISSION;
126 		else
127 			list->mtl_error = MEMSTAT_ERROR_VERSION;
128 		free(buffer);
129 		return (-1);
130 	}
131 
132 	if (size == 0) {
133 		free(buffer);
134 		return (0);
135 	}
136 
137 	if (size < sizeof(*mtshp)) {
138 		list->mtl_error = MEMSTAT_ERROR_VERSION;
139 		free(buffer);
140 		return (-1);
141 	}
142 	p = buffer;
143 	mtshp = (struct malloc_type_stream_header *)p;
144 	p += sizeof(*mtshp);
145 
146 	if (mtshp->mtsh_version != MALLOC_TYPE_STREAM_VERSION) {
147 		list->mtl_error = MEMSTAT_ERROR_VERSION;
148 		free(buffer);
149 		return (-1);
150 	}
151 
152 	if (mtshp->mtsh_maxcpus > MEMSTAT_MAXCPU) {
153 		list->mtl_error = MEMSTAT_ERROR_TOOMANYCPUS;
154 		free(buffer);
155 		return (-1);
156 	}
157 
158 	/*
159 	 * For the remainder of this function, we are quite trusting about
160 	 * the layout of structures and sizes, since we've determined we have
161 	 * a matching version and acceptable CPU count.
162 	 */
163 	maxcpus = mtshp->mtsh_maxcpus;
164 	count = mtshp->mtsh_count;
165 	for (i = 0; i < count; i++) {
166 		mthp = (struct malloc_type_header *)p;
167 		p += sizeof(*mthp);
168 
169 		if (hint_dontsearch == 0) {
170 			mtp = memstat_mtl_find(list, ALLOCATOR_MALLOC,
171 			    mthp->mth_name);
172 		} else
173 			mtp = NULL;
174 		if (mtp == NULL)
175 			mtp = _memstat_mt_allocate(list, ALLOCATOR_MALLOC,
176 			    mthp->mth_name);
177 		if (mtp == NULL) {
178 			memstat_mtl_free(list);
179 			free(buffer);
180 			list->mtl_error = MEMSTAT_ERROR_NOMEMORY;
181 			return (-1);
182 		}
183 
184 		/*
185 		 * Reset the statistics on a current node.
186 		 */
187 		_memstat_mt_reset_stats(mtp);
188 
189 		for (j = 0; j < maxcpus; j++) {
190 			mtsp = (struct malloc_type_stats *)p;
191 			p += sizeof(*mtsp);
192 
193 			/*
194 			 * Sumarize raw statistics across CPUs into coalesced
195 			 * statistics.
196 			 */
197 			mtp->mt_memalloced += mtsp->mts_memalloced;
198 			mtp->mt_memfreed += mtsp->mts_memfreed;
199 			mtp->mt_numallocs += mtsp->mts_numallocs;
200 			mtp->mt_numfrees += mtsp->mts_numfrees;
201 			mtp->mt_sizemask |= mtsp->mts_size;
202 
203 			/*
204 			 * Copies of per-CPU statistics.
205 			 */
206 			mtp->mt_percpu_alloc[j].mtp_memalloced =
207 			    mtsp->mts_memalloced;
208 			mtp->mt_percpu_alloc[j].mtp_memfreed =
209 			    mtsp->mts_memfreed;
210 			mtp->mt_percpu_alloc[j].mtp_numallocs =
211 			    mtsp->mts_numallocs;
212 			mtp->mt_percpu_alloc[j].mtp_numfrees =
213 			    mtsp->mts_numfrees;
214 			mtp->mt_percpu_alloc[j].mtp_sizemask =
215 			    mtsp->mts_size;
216 		}
217 
218 		/*
219 		 * Derived cross-CPU statistics.
220 		 */
221 		mtp->mt_bytes = mtp->mt_memalloced - mtp->mt_memfreed;
222 		mtp->mt_count = mtp->mt_numallocs - mtp->mt_numfrees;
223 	}
224 
225 	free(buffer);
226 
227 	return (0);
228 }
229